I bought a hand crank can opener (Oxo) because of the good online feedback and only use the "shake" dry approach. It quickly developed rust in between the metal. If I invest the time and scrub, I can remove most of the rust.

When I initially posed the maintenance question in IRC concerning rust and utensils and kitchenware in general, I got suggestions from "spend a little on a decent one" to "you want stainless steel". I stored both answers as helpful for future purchases.

Just recently I noticed two can openers in the office pantry that both show rust. Obviously these were neglected and showed more corrosion. After seeing this, I am curious if rust is actually normal and harmless. Are there more expensive stainless steel can openers that are rust resistant? Should I be drying more rigorously? I just thought of another possibility: should I keep the can opener in a jar of cooking oil?

9 Answers
9

First, I would suggest you buy a higher quality can opener. I have a Swing-A-Way that I inherited from my grandmother. I think it's older than me.

Second, don't submerge the can opener in water every time you use it. I only full out wash it on the rare occasion I splash or drop something all over it. The rest of the time I just use my dishcloth to wipe the blade and handles clean and let it dry in the dish rack before putting it away.

I don't have an answer to your "choice of material" question, though I would tend to believe stainless steel is your best bet.

However, for preventing rust: Try cranking a paper towel through the spokes after you use and/or wash it, if that's where the rust is accumulating. It cleans and dries them very well, and I don't know if it's what's preventing rust on ours, but I do that every time and haven't noticed rust yet.

Rust (iron oxide) requires exactly three things to form: Iron, oxygen, and water. The first two are already in abundance, so in order to prevent rust, you need to minimize the third. Keep the can opener as dry as possible. Use a cloth or paper towel.

Stainless steel is corrosion "resistant"; it does not corrode or rust as easily as untreated iron or steel, but it can still corrode over time and will certainly tarnish. Again, the way to prevent this is to keep it dry.

I would not keep the can opener in a jar of cooking oil, because cooking oil can go rancid. Culinary-grade mineral oil would be okay, but it seems like a waste of oil to me; as long as you keep it dry, it won't rust.

Having said that, my can opener is pretty rusty and it doesn't bother me. Rust is definitely normal, and as long as the rust doesn't get into your food (which has never happened to me) then it is also completely harmless. It might not open cans as well if the blade itself is rusted, and that could potentially leave sharp edges on the opened can or lid, but that's highly individual and I'm sure you should be able to spot if and when that's happening. Personally, I don't bother to thoroughly dry can openers, because they're cheap enough that I can just buy a new one if they rust really badly.

But in general, yes, the two things you can do to minimize rusting on a can opener (or any other metal equipment) is to (a) use stainless steel and (b) keep it dry.

I have a lot of canned food and have gone through my share of can openers. I'm generally OK with a rusty can opener, but I don't like the rust flakes getting into my food. I can't bear that metallic taste.

While I don't mind buying a new can opener (they sell them at the dollar general for two dollars), but I find it a bit wasteful.

This may sound a bit un-orthodox, but I use rubbing alcohol (90% or higher). I have a jar filled with it next to the sink, so I will rinse the can opener off, dip it in the jar of alcohol, and put it back in the drawer. It dries fine in there.

I generally wash the opener by hand but occasionally run it though the dishwasher. In both cases, after it is dry, I occasionally put drops of food grade mineral oil on the gears, etc. I use almond oil. I also use almond oil on my wooden cutting boards. (almond oil is a wonderful skin softener, too).

Swing-a-way was a great brand back in the day but the company/name has been sold out of China. That may account for the quality now. John J Steuby Co purchased the manufacturing equipment and making EZ-DUZ-IT can opener. It is made in the USA and the packaging is cheesy but this is the original Swing-a-Way with a new name.

I've flagged the other answer for moderator attention. I believe it should be possible for you to edit your own answers even with one reputation point. Maybe someone will correct me if I'm wrong on that.
–
Chris SteinbachJan 26 at 20:25

You might want to register your account to make sure everything works - the old and new posts are on the same userid, so you should be able to do what you like with them. I think this link should work: stackoverflow.com/help/creating-accounts
–
Jefromi♦Jan 26 at 22:35